No. I AM right. There's no "probably" involved here.
You can make a small boot bigger, but shrinking a big boot is dumb, and only done in case where it's absolutely necessary for reasons that are complex and not fun to get into online.
If you fit the 25.5, you fit the 25. period.
The difference between a 25.5 and 26 isn't just length. It's VOLUME. Your foot is, believe it or not, and contrary to most bootfitters' opinions, a 3-dimenensional structure, and overall VOLUME affects fit, big time, as does foot shape, etc etc etc.
If you told your rep that you fit the 25.5, and he let you order a 26, then he's a jackass, and probably shouldn't have the job he has. The 25 and the 25.5 are essentially the SAME FUCKING BOOT, and this decision should have been a no brainer. Shit, half the time you order a boot, on pro form, in a half size, they send you the full size down without even telling you (ie order a 25.5, get a 25).
now, NO MORE FUCKING BOOT THREADS ON NEWSCHOOLERS. Please. It's getting really fucking stupid.